1. Field of the Invention
The invention generally relates to video distribution systems and, more particularly, to video distribution systems that distribute deconstructed video through communications networks.
2. Description of the Background Art
Video transmission through communications networks such as the INTERNET has become ubiquitous. Typically, the video is encoded using a compression algorithm such as MPEG-2 or Quicktime and transmitted as a single compressed bitstream to the user. The user's equipment comprises a plurality of compressed-video decoders that can decode various forms of encoded video. However, if the user's equipment is of a type that has limited computing power, the decoded image sequence may be distorted, or otherwise have poor quality.
One method that is used to match the quality of the encoded imagery to the capabilities of the user equipment is to encode a plurality of bitstreams where each stream represents a different level of image quality. The user then selects a bitstream from the plurality of encoded bitstreams. The quality of the video encoded into the selected bitstream matches the processing power of the user's equipment, i.e., a small hand-held computing device capable of low resolution video presentation would select a low resolution bitstream. As such, the user receives and decodes the selected bitstream in a manner that matches the capabilities of their device.
Such systems require the user to apriori understand the capabilities of their decoder and select an appropriate bitstream. Many times such selection is not possible or it is accomplished by trial and error, i.e., the user repeatedly selects bitstreams until an appropriate one is found. Furthermore, transmitting a plurality of encoded bitstreams where each bitstream comprises a full representation of an image sequence consumes an enormous amount of bandwidth within the communications network and a large amount of storage space on a server.
Therefore, there is a need in the art for a method and apparatus that deconstructs the video in a hierarchical manner, transmits each level of deconstructed video in the hierarchy, and enables user equipment or a network interface device to reconstruct a video stream from select levels of the deconstructed video that is commensurate with the capabilities of the user equipment.